7/14/15: More Hit and Miss

Yesterday some showers and thunderstorms developed with daytime heating and a similar scenario is projected to occur today as well.  The High Resolution Rapid Refresh (HRRR) guidance for projected thunderstorms is presented below.  It is not meant to be what is “exactly” going to happen, but rather guidance to the fact that hit and miss storms will likely occur during the day.

HRRR Radar Projection
HRRR Radar Projection

The activity today looks to be slightly less widespread than even yesterday, plus there are always the localized exception, but precipitation amounts today are expected to be light for the locations that do record some rainfall.

Maximum temperatures should be a bit warmer than yesterday with temperatures climbing into the mid to upper 80s this afternoon.

July 14, 2015 Maximum Projection
July 14, 2015 Maximum Projection

The maximums on Wednesday will in turn, be another few degrees warmer baring any unforeseen cloud cover.  90° potential tomorrow is far more likely than today.

Wednesday Maximum Potential
Wednesday Maximum Potential

Not only will the warmth continue, but the dew points will remain in the 60s or even locally around 70°.  Today, mainly 60s for dew points (50s in SW North Dakota).

Dew point projection for later this afternoon (Tuesday, July 14)
Dew point projection for later this afternoon (Tuesday, July 14)

But with slightly warmer temperatures tomorrow will also come slightly higher low level atmospheric moisture so on Wednesday, Dew  Points are probably going to be a bit closer to 70° in some parts of eastern North Dakota on Wednesday.

Projected Dew Points Wednesday, July 15, 2015
Projected Dew Points Wednesday, July 15, 2015

The warm and humid air mass with daily hit and miss storms is projected through Saturday.  A disturbance passing through the region later Wednesday into Thursday should trigger off more abundant storms than what is expected today, or occurred yesterday, then on Saturday ahead of a cold front, a bit more widespread activity may occur that day.  Each day will have some storms, those are the days when the most widespread activity is expected.  In the short term, although an isolated severe storm could certainly occur today (probably will in fact), tomorrow will be the best day for severe weather probabilities until the weekend.

This weekend an adjustment to the upper level wind flow will bring in cooler air into the area and that transition will likely mean thunderstorms and probably more severe weather.  Then Sunday into the middle of next week cooler than average temperatures, probably maximums in the 70s is foreseen.

Next 10 Day 500 mb heights / anomalies from WMO-Essential ECMWF
Next 10 Day 500 mb heights / anomalies from WMO-Essential ECMWF

Warm and humid to cool and drier (both atmospherically and rain wise) looks to be the transition over the next week, but the emphasis will be hit and miss storms, some severe, otherwise warm and humid through Saturday.

Daryl Ritchison